1. Field of the Invention
The present invention relates to a substrate consisting essentially of regenerated collagen fibrils, and more particularly it relates to the substrate of regenerated collagen fibrils useful for cell culture and as a carrier for measuring adhesion activity of blood platelets.
2. Brief Description of the Prior Art
The technology for utilizing useful substances obtained by culturing animal cells in a large amount and isolating the products has been watched with keen interest as one of the fields of biotechnology. Also, in the academic studies of artificial organs, studies have been actively performed for artificial organs of the type that the animal cells are incorporated therewith.
In both cases, it is most important to carry out a mass proliferation by culturing the cells removed from living bodies while keeping the physiological activities of the cells. Collagen plays a vital role as a supporting substance, namely substrate, for cells which constitute organs and tissues in the living body. Accordingly, it can be said that collagen is the best and an excellent substrate for cell culture among the existing substances.
In general, animal cells grow and proliferate while adhering to the substrate, and thus the existence of the effective substrate is essential for maintaining the activities of the cells. For the mass culture and mass proliferation of animal cells, the shape of the substrate in the form of a fine particle rather than a flat plate is remarkably advantageous since it is necessary for the substrate to have a very large surface area. Thus, recently, beaded fine particles or microsphere carriers are being employed; for example, a crosslinked dextran has been developed and marketed as beaded substrate for the mass culture of cells, (see Catalogue Cytodex 1, "Beaded Microcarrier for Cell Culture" from Pharmacia Japan Co., Ltd.).
As described above, collagen plays a role as substrate a for various types of cells in the living body and has been utilized as a substrate for cell culture. However, the conventional collagen has only been used as a substrate coated on the surface of various articles of plastics or glass, or also, has only been used for cell culture on the surface or inside of a gel in the form of collagen gel obtained by neutralizing an acid solution of collagen under physiological conditions.